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No. 624,|4|. Patented May 2, I899. R. 8. WHITE.

ELECTRIC METER.

(Application filed Sept. 2, 1898.)

2 Sheets-Sheei L (No Model.)

WITNESSES INVENTDR my 1, A41:

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N0. 624,l4l. Patented May 2, I899. H. 8. WHITE.

ELECTRIC METER.

(Application filed Sept. 2, 1898.)

2 Shams-Sheet 2.

{No Model.)

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UNITED STATES PATENT OFFICE.

ROGER S. IVIIITE, OF NEYV YORK, N. Y.

ELECTRIC METER.

SPECIFICATION forming part of Letters Patent No. 624,141, dated May 2,1899.

Application filed September 2, 1898. Serial No. 690,129. N0 mod -J I T0at whom, it may concern:

Be it known that I, ROG-ER S. WVI-IITE, acitizen of the United States,residing in the borough of Brooklyn, in the city and State of New York,have invented certain new and useful Improvements in Electric Meters, ofwhich the following is a specification.

My invention relates to various new and usefulimprovements in electricmeters of the type employing an electric motor influenced, by thecurrent to be measured and operating a register-train, themotor-armature being provided with a retarding device influencedpreferably, by the motor field-magnets and by means of which the properload upon the motor will be secured.

The object of my invention is to provide a meter of this type capable ofvery accurate registration and of a simple construction. In order toprovide a motor-meter which shall quickly respond to changes in load andwhich shall accurately register the current, itis desirable that thearmature should be very light and thatthe magnetic field should be asintense as possible. At the present time motormeters are made employinga retarding device which comprises a disk of non-magnetic metal carriedby the armature-shaft and in some instances forming a base or supportfor the armature-coils. This disk is influenced either by thefield-magnets of the motor or by a separate magnet or magnets. Theemployment of a disk of non-magnetic metal on the armature-shaft makesthe armature unduly heavy, so that it does not quickly and accuratelyrespond to changes in the current. In order to overcome this diflicultyand to make an armature as light as possible, I employ a flat annularring as a retarding device, the extent of surface of such ring beingsubstantially equal to the magnetic field in which it rotates. Byemploying a non-magnetic annular ringinstead of a disk, as heretoforeused, I am enabled to save a considerable portion of unnecessary metal,and I am thereby enabled to make the armature of a minimum weight. Thearmature-coils of my improved motor-meter are preferably carried on aflat non-metallic support, such as a sheet or disk of mica, and the flatannular ring which constitutes the retarding device is preferablysecured to such non-1netallic disk either on top of the armature-coils or onthe opposite side of the disk from the armature-coils, whereby a verylight armature will be secured which can be made of a relatively largediameter and will be subject to all changes in the current to bemeasured.

In motor-meters as now constructed it is the custom to employ permanentfield-magnets foreffectingthe rotation of the armature. When suchpermanent field-magnetsare employed, it has been found that abnormalconditions, such as short-circuiting or reversal of the current, affectsthe magnetism and thereby influences the operation of the meter. \Vithpermanent field-magnets it has been found impossible to secure intensemagnetic fields, since an intensely-magnetized permanent magnet quicklyloses its magnetism, and consequently the rotative effect of thearmature under the influence of a definite amount of current would begradually decreased, so that the motor would be inaccurate. It istherefore the custom in motormeters as now constructed to firstintensely magnetize the permanent field-magnets and to then weaken suchmagnetism in order to obtain a relatively constant magnetic field. Asstated, therefore, at the present time it is neither possible to employarmatnres of a minimum lightness, nor is it possible to obtainfieldunagnets of amaximum strength, so that the present meters do notrespond accurately and instantly to changes in the current whichinfluence them.

In order to overcome the objections before noted to the employment ofpermanent field- Jagnets, I provide the field magnet or magnets of myimproved meter with a coil thereon by which the permanent magnetism willbe retained and by which an intensely-mag netic field may be secured. Inorder to effectively regulate the speed of rotation of my improvedmotor-meter, I prefer to employ'in conjunction with the permanentfield'magnets one or more retarding-magnets having windings thereon andarranged at the neutral point or points on the armature between thefield-magnets, whereby such retarding magnet or magnets willadditionally serve to retard the speed of rotation of the armature bytheir action upon the retarding device. By varying the number of turnsof the coil or coils on the retarding magnet or magnets it is possibleto very accurately regulate the retarding effect and to thereby secure amotor-meter wherein the armature will instantly and accurately respondto and indicate c hanging currents which may influence it, making itunnecessary to change the more expensive windings on the permanentfield-magnets.

In order that my invention maybe better understood, attention isdirected to the ac companying drawings, forminga part of thisspecification, and in which Figure I is a sectional View showing onefield-magnet and illustrating the preferable construction of armatureand commutator, and Fig. 2 a diagrammatic view illustrating the electricconnections.

I11 both of the above views corresponding 1 parts are represented by thesame numerals of reference.

1 represents a shaft mounted in a suitable framework and preferably oncone or jewel bearings, so as to rotate with a minimum friction. Thisshaft is provided with a worm 2 at its upper end, which operates theregistertrain, (not shown,) or it may operate the register-train inanysuitable way. Carried upon the shaft 1 is asleeve 23, secured theretoby a set--screw I or in any suitable way.

5 is a thin disk of non-metallic material, preferably mica, whichconstitutes the body or support of the armature. This disk is made asthin as possible, so that an armature of great lightness will besecured. The disk is secured to the sleeve in any suitable wayas, forexample, by a washer (5. The disk 5 carries the armature-coils 7, whichare arranged flat upon the disk and secured in place by an adhesivesubstance, such as shellac. The coils connect to a commutator 8, made ofas small diameter as possible, and bearing upon said commutator are thetwo brushes 9 f), mounted in any suitable way Both the bars of thecommutator S and the brushes 9 f) are heavily gold-plated, whereby Iavoid any tendency of oxidation and secure bright contact-surfaces atall times.

10 represents the retarding device, which preferably comprises a flatannular ring, as shown, which ring is made of a non-magnetic metal, suchas aluminium. I prefer to make the retarding device 10 of aluminium inorder that the rotating parts of the armature may be made of a minimumlightness. Preferably the flat annular ring 10 is mounted on the coils 7of the armature and is secured in place thereto in any suitable waysuch, for example, as by the small spring-clips 11, which clamp the ringin place. Instead of using clips forthis purpose it will of course beseen that the retarding-ring 10 may be secured in place by means of anadhesive substance, by rivets, or in any other suitable way. Itis notnecessary that the retarding-ring 10 should be placed on top of thecoils 7, as explained, since said retarding-ring may be secured on theunder side of the disk 5, as will be understood. It will of course befurther understood that the retarding-ring maybe mounted elsewhere onthe shaft than in conjunction with the motor-armatu re and be affectedby separate and independent retarding-magnets. It is preferable,however, that the retardingring should be carried on the armature, as bysuch a construction I am enabled to make the armature of a minimumlightness and to utilize the field-magnets of the motor for the purposeof opposing the retardation of the armature.

12 12 represent the field-magnets of the motor, which are preferablyarranged tan gentially to the armature, as shown in Fig. 2, and whichmay beof' any suitable construction.

, These field-magnets are permanently magnetixed,and their fields are asintensely magnetic as can be secured. In order to prevent thefield-magnets from losing their magnetism in use, I provide each magnetwith a separate coil 1.3 thereon, by means of which. the permanentmagnetism will be always maintained of a constant intensity.

My improved meter will be adjusted to the proper standard by varying tothe correct extent the retarding effect upon the retarding device. Thisregulation may be thus effected by varying the length of turns of thecoil or coils 1 3. I prefer, however, to make the permanent magnets 12and their coils always of a constant standard and to utilize one or moreseparate retarding-magnets 1t, cooperating with the armature on theneutral line between the two field-magnets. In Fig. I illustrate one ofthese retarding-magnets; but it will be obvious that two of them may beused at diametric points on the armature. The retarding magnets l-t aresomewhat smaller than the field-magnets 12. Theyare permanentlymagnetized and they are provided each with a coil 15 thereon, thelengths or number of turns of which may be varied to adjust the speed ofrotation of the armature to the correct point.

In connecting my improved motor-meter in circuit I prefer to adopt thearrangement illustrated in Fig. 2. l6 10 represent the supplymains, 17and 18 the branches leading therefrom, and 19 20 theconsumption-circuit, having the translation devices 21 therein. Thebranch 18 leads to a binding-post 22, and the two coils 13 of thefieldanagnets will be connected in series with each other and with thecoil or coils of the retarding magnet or magnets between saidbinding-post and a second binding-post 23, as shown. The brushes 0 ofthe motor-armature are connected in a separate shunt 2t across saidbinding-posts, as shown. A wire connects the bindingpost 23 with theconsumption-main 19.

In operation the circuit including the permanent field-magnet coilstakes the place of a separate shunt necessary in meters of this typeemploying simgle permanent field-magnets. By making use of permanentfieldmagnets each with a separate coil thereon,

IOO

by which its magnetic fleld may be always maintained of a relativelyhighintensity, and by employing an armature of the type described havinga retarding device carried thereby, comprising a flat annular ring, I amenabled to obtain a motor-meter which will respond with great accuracyto variations in the current, since the armature is of a mini mumlightness and the fields of a maximum strength.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is as follows:

1. In an improved motor-meter, the combination of an armature influencedby the current to be measured, .a retarding device for imposing'a'loadupon the armature, a permanent field-magnet with respect to which thearmature rotates, and a magnetizing-coil on such field-magnet,substantially as set forth.

2. In an improved motor-meter, the combination of an armature influencedby thecurrent to be measured, a retarding-ring for imposing a load uponthe armature, a permanent field-magnet with respect to which thearmature rotates, and a magnetizing-coil on such field-magnet,substantially as set forth.

3 111 an improved motor-meter, the combination of an armature influencedby the current to be measured, a retarding-ring for i1n-' posing a loadupon the armature, a permanent field-magnet with respect to which thearmature rotates, said retarding-ring also operating in the field ofsuch permanent fieldmagnet, and a magnetizing-coil on such fieldmagnet,substantially as set forth.

i. In a motor-meter, the combination with an armature influenced by thecurrent to be measured, of a field-magnet with respect to which thearmature rotates, a retarding device carried by the motor-armature andinfluenced by the field of the permanent fieldmagnet, and a separateretarding-magnet arranged at the neutral point on said armature and alsoinfluencing the retarding-device, substantially as set forth.

5,. In a motor-meter, the combination with an armature influenced by thecurrent to be measured, of a field-magnet with respect to which thearmature rotates, a retarding-ring carried by the motor-armature andinfluenced by the field of the permanent field-magnet, and a separateretarding-magnet arranged at the neutral point on said armature and alsoinfluencing the retarding-ring, substantially as set forth.

6. In a motor-meter, the combination with an armature comprising a flatdisk of nonmetallic material, of armature-coils carried by said disk, afield-magnet with respect to which the armature rotates, and aretardingring for retarding the rotation of said armature, substantiallyas set forth.

7. In a motor-meter, the combination with an armature comprising a flatdisk of nonmetallic material, of armature-coils carried by said disk, afield-magnet with respect to which the armature rotates, and aretardingring influenced by the field of said field-magnet for retardingthe rotation of said armature, substantially as set forth.

8. In a motor-meter, the combination with an armature comprising a flat,non-metallic disk, armature-coils carried by said disk and a flat,non-magnetic retarding-ring carried by the armature, of a field-magnetwith respect to which the armature rotates, said field-magnet alsoinfluencing the retarding-ring, substantially as set forth.

9. In a motor-meter, the combination with an armature comprising a flat,non-metallic disk, armature-coils carried by said disk, and a flat,non-magnetic retarding-ring secured to said flat, non'metallic diskabove the armature-coils, of a field-magnet with respect to which thearmature rotates, saidfleld-m agnet also influencing the retarding-ring,substantially as set forth.

10. In a motor-meter, the combination with an armature comprising aflat, non-metallic disk, armature-coils carried by said disk, and aflat, annular, retarding-ring made of aluminiu m, of a field-magnet withrespect to which the armature rotates, said field-magnet alsoinfluencing the retardingring, substantially as set forth.

This specification signed and witnessed this th day of August, 1898.

' ROGER S. IVI'IITE.

Witnesses:

FRANK L. DYER, JNo. R. TAYLOR.

